The present invention relates to the polymerization of olefins. In another aspect the present invention relates to the preparation of catalysts useful for the polymerization of olefins.
A number of catalyst of varying activity for the polymerization of olefins have been prepared by forming a solution of a magnesium-containing component with a transition metal-containing component (hereinafter referred to as Mg-TrMe solution) and then contacting the Mg-TrMe solution with a reactant which results in the formation of a particulate catalyst or catalyst precursor. Some examples of such catalysts are shown in U.S. Pat. Nos. 4,477,588; 4,394,291; 4,562,168; 4,429,089; 4,537,870; and 4,363,746, the disclosures of which are incorporated herein by reference.
One problem that is encountered in the preparation of such solid catalyst components from a solution is the formation of significant amounts of fine particulate material. The presence of very fine particles can result in problems in the handling of the catalyst and the resulting polymer. Accordingly, in order to produce catalysts satisfactory for large scale commercial use it is generally necessary to carry out some additional step or treatment to obtain particulate catalyst components of the desired particle size.
One object of this invention is to provide new catalyst compositions that provide particularly high activity in the polymerization of olefins while at the same time being free of various disadvantages when used in the production of olefin polymers on a large commercial scale.
Another object of the present invention is to improve the particle size of particulate catalyst components prepared by the processes disclosed in U.S. Pat. Nos. 4,477,588; 4,394,291; 4,562,168; 4,429,089; 4,537,870; and 4,363,746.
Other aspects, objects, and advantages of the present invention will become apparent from the following disclosure.